Gas Chromatography is a technique used to resolve a mixture of compounds for the purpose of identification and quantitation. Suitable for compounds that are capable of generating a vapour pressure when heated to a temperature of up to 450°C. Separation is affected by their interaction between a solid or liquid stationary phase and a gaseous mobile phase. For very volatile compounds, separation is essentially a physical process, for semi-volatile compounds, polarity with chemical interactions become more of a contribution.